Vibratory feeder bowls and parts separators typically urge parts upwardly along a helical parts path by vibrating the helical path both axially along, and rotationally about, its central axis. A vibratory drive unit is required to impart the necessary vibratory feed motion to the feeder bowl.
In the design of a vibratory parts feeder, an established industry practice is to attach the feeder bowl to a top member of the drive unit, wherein the top member and a stationary base member of the drive unit are connected by a plurality of drive springs. Vibratory action is created at the base member, by suitable means, which is transferred to the top member via the drive springs. By establishing an appropriate vibratory direction, and properly positioning the drive springs, the feeder bowl is made to vibrate in either a clockwise or counter clockwise direction. Parts within the feeder bowl are then correspondingly transported upwardly along the helical parts path to a bowl exit location.
Designers of vibratory parts feeders have utilized several approaches in attaching a feeder bowl to a drive unit. One such prior art approach is shown with respect to the vibratory parts feeder 10 of FIG. 1. Referring to FIG. 1, a feeder bowl 12 is attached to a drive unit 20 by means of clamp nuts 14. The drive unit 20 includes a base member 22 and a top member 24. A number of drive springs 26 are connected between the base member 22 a corresponding number of spring pads 28 of top member 24. At least one vibratory driver 30 generates vibratory action at the base member 22 which is transmitted to the top member 24 via the drive springs 26. The clamp nuts 14 are adjustably mountable to the top member 24 by fasteners 16. The fasteners 16 may be adjustably positioned relative to the top member 24 to thereby clamp a lower flange 18 of the feeder bowl 12 to a vertical wall 32 of the top member 24.
It is also known in the vibratory parts feeding industry to provide vibratory drive units, such as drive unit 20 of FIG. 1, with the ability to vibrate parts within bowl 12 in either a clockwise or counter-clockwise direction. As shown in FIG. 1, drive springs 26 are attached to spring pads 28 of top member 24, and to spring pads 29 of base member 22, to thereby provide vibratory action in one direction. However, drive springs 26 may alternatively be attached to spring pads 28' of top member 24, and to spring pads 29' of base member 22, to thereby provide vibratory action in an opposite direction. Thus, vibratory parts feeder 10 is configurable for bidirectional vibratory motion depending upon the attachment locations of drive springs 26. An example of such a bidirectional vibratory drive unit is shown and described in applicant's U.S. Pat. No. 5,314,058, the contents of which are hereinafter incorporated by reference.
Although the foregoing clamp nut approach facilitates the easy removal, positioning and attachment of feeder bowls 12 to the drive unit 14, it has several inherent drawbacks. First, efficiency in transmission of vibratory action through the drive springs 26 to the feeder bowl 12 is dependent upon the location of the spring pads 28 relative to the weight of the top member 24. Generally, the less top member 24 weight located above the spring pads 28, the more efficient the transmission of vibratory action. In the vibratory parts feeder 10 of FIG. 1, the bulk of the clamp nuts 14 are located above the spring pads 28, thereby decreasing vibratory transmission efficiency.
Secondly, in adjusting or replacing a feeder bowl 12, the clamp nuts 14 must be loosened. Unless the clamp nuts 14 are manually held in position, they may rotate when being loosened or tightened so that the bulk of the clamp nuts 14 are directed downwardly toward the base member 22. The same may occur if the vibratory action of the parts feeder 10 works the clamp nuts 14 loose. Since three or more clamp nuts 14 are typically used with the vibratory parts feeder 10, repeated repositioning of the clamp nuts 14 becomes a tedious and laborious task.
Thirdly, the lower flange 18 of the feeder bowl 12 is in constant contact with the fasteners 16 in the vibratory parts feeder 10 shown in FIG. 1. Since the fasteners are often threaded bolts, such constant contact, particularly when removing, adjusting or replacing a feeder bowl 12, may strip the threads thereby requiring periodic replacement of fasteners 16.
Finally, the clamp nut arrangement of FIG. 1 may accommodate only one size of feeder bowls 12. An application specifying a differently sized feeder bowl 12 requires that an appropriately sized drive unit 20 be provided as well. As a result, users of vibratory parts feeders must keep an inventory of multiple-sized drive units for use with the various feeder bowls. Such an inventory can be expensive to establish, store, and maintain.
What is therefore needed is an easily adjustable clamp nut arrangement for a vibratory parts feeder that maximizes transfer of vibratory efficiency while minimizing parts wear. Ideally, such a parts feeder should further accommodate various sized feeder bowls.